Patau syndrome is a serious genetic disorder known in medicine as "Trisomy 13" and is caused by the presence of an extra copy of the 13th chromosome. This chromosomal difference can affect many organs, primarily the brain, heart, face, eyes, kidneys, and nervous system. Usually detected during pregnancy through prenatal screening tests, ultrasound examinations, and genetic diagnostic methods, Patau syndrome is a rare condition that presents with severe clinical findings. Although there is no definitive cure for the disease, early diagnosis, pregnancy follow-up, a multidisciplinary approach, supportive care, and genetic counseling processes are of great importance for both the family and the baby.
| Summary Information Table | |
|---|---|
| Title | Short Description |
| Other name | Trisomy 13 |
| Primary cause | Extra copy of the 13th chromosome |
| Diagnosis | Ultrasound, NIPT, CVS, amniocentesis, karyotype analysis |
| Symptoms | Heart, brain, facial, eye, kidney, and developmental anomalies |
| Treatment | No definitive cure; supportive and family-centered care is applied |
| Follow-up | Genetics, obstetrics, neonatology, cardiology, neurology, and psychological support |
What Does Patau Syndrome, Also Known as Trisomy 13, Mean?
Patau syndrome is a genetic chromosomal disorder also known as "Trisomy 13". While the human body normally has two of each chromosome, in this syndrome, the 13th chromosome is present in three copies. The term "trisomy" itself refers to the presence of an extra chromosome. This extra genetic material can significantly affect the baby's developmental process and lead to structural anomalies in numerous organ systems.
Trisomy 13 often causes developmental problems in the early stages of pregnancy. While some pregnancies result in miscarriage, serious health problems can be observed in babies born alive. Heart anomalies, central nervous system problems, facial structure differences, and developmental delay are among the most frequently encountered findings.
Patau syndrome is a rare condition, but it holds special importance in prenatal diagnostic processes due to its severe course. Today, thanks to advanced genetic diagnostic methods, risk assessment can be performed during pregnancy.
What Causes Patau Syndrome?
The primary cause of Patau syndrome is the presence of an extra copy of the 13th chromosome. This condition generally stems from random genetic errors occurring during cell division. Under normal conditions, a total of two copies of the 13th chromosome are transferred to the baby, one from the mother and one from the father. However, in the case of Trisomy 13, there are three copies.
The mechanisms by which Patau syndrome occurs may include:
- Full Trisomy 13
- Mosaic Trisomy 13
- Translocation-type Trisomy 13
.
The most common form is full Trisomy 13, where an extra chromosome is present in all cells of the body. In mosaic Patau syndrome, however, only some cells have the extra chromosome. Therefore, symptoms may follow a milder course.
Advanced maternal age is considered one of the risk factors for chromosomal anomalies. Especially in advanced maternal age pregnancies, prenatal screening and genetic counseling processes become more important.
What Are the Symptoms of Patau Syndrome?
Patau syndrome is a serious genetic disease that can affect numerous organ systems. Symptoms can begin during the baby's developmental process and become more pronounced after birth.
The most common Patau syndrome symptoms are as follows:
- Congenital heart diseases
- Brain development anomalies
- Cleft lip and palate
- Small eye structure (microphthalmia)
- Extra fingers or toes (polydactyly)
- Kidney anomalies
- Low birth weight
- Feeding difficulties
- Muscle tone problems
- Neurological developmental delay
Severe respiratory problems and seizures may also be observed in some babies. Due to anomalies in brain development, learning and motor development processes can be significantly affected.
The severity of Patau syndrome symptoms can vary depending on the type of chromosomal difference. Milder clinical pictures may be seen in cases of mosaic Trisomy 13.
How Is Patau Syndrome Detected During Pregnancy?
Patau syndrome can be noticed during pregnancy in many cases. Today, thanks to prenatal screening tests and detailed ultrasound examinations, chromosomal anomalies can be evaluated at an early stage.
Findings that draw attention during pregnancy may include:
- Brain development anomalies
- Heart problems
- Facial anomalies
- Developmental delay
- Extra fingers or toes
- Kidney problems
- Amniotic fluid changes
.
Particularly if suspicious findings are detected during detailed ultrasound examination, advanced genetic diagnostic methods can be resorted to. NIPT (Non-Invasive Prenatal Test), which has become widespread in recent years, allows the examination of DNA fragments belonging to the baby from the mother's blood and helps perform a risk assessment in terms of Trisomy 13.
However, NIPT is a screening test; invasive genetic tests may be required for a definitive diagnosis.
How Is Patau Syndrome Diagnosed?
Prenatal screening tests and genetic analyses hold great importance in the diagnosis of Patau syndrome. When suspicious ultrasound findings are observed or a high risk is detected in screening tests, advanced examinations are performed.
The methods used in diagnosis are:
- Ultrasound examination
- NIPT
- CVS (Chorionic Villus Sampling)
- Amniocentesis
- Karyotype analysis
- Genetic examinations
Definitive diagnosis is generally made by karyotype analysis. In this analysis, the baby's chromosomal structure is examined to evaluate whether the 13th chromosome is extra.
The diagnostic process is important not only from a medical standpoint but also in terms of preparing families psychologically. Therefore, genetic counseling support plays a critical role.
Can Patau Syndrome Be Treated?
There is no definitive cure for Patau syndrome. Because at the root of the disease lies a chromosomal difference, and it is not possible to completely correct the existing genetic structure.
The treatment approach is mostly built upon supportive care. The aim is to improve the baby's quality of life and manage the emerging complications.
The following areas are important during the treatment process:
- Respiratory support
- Nutritional support
- Monitoring of heart anomalies
- Neurological evaluation
- Surgical interventions
- Physical therapy
- Family-centered care
Surgical interventions can be planned for certain congenital heart diseases or structural anomalies. However, the treatment decision is evaluated individually for each baby.
Life Expectancy and Prognosis in Patau Syndrome
Because Patau syndrome is a genetic disease with a severe course, life expectancy may be limited in many cases. Especially in babies with severe organ anomalies, the first days or first months of life carry critical importance.
Heart anomalies, severe brain development problems, and respiratory failure are the primary factors affecting life expectancy. However, the prognosis is not the same in every baby. Longer life spans can be observed especially in cases of mosaic Patau syndrome.
In recent years, thanks to the development of neonatal intensive care facilities and the improvement of supportive care processes, life expectancy can be prolonged in some patients. Nevertheless, multidisciplinary follow-up holds great importance.
Differences Between Patau Syndrome, Down Syndrome, and Edwards Syndrome
Although Patau syndrome, Down syndrome, and Edwards syndrome are in the group of chromosomal anomalies, they affect different chromosomes.
- Down syndrome → Trisomy 21
- Edwards syndrome → Trisomy 18
- Patau syndrome → Trisomy 13
Patau syndrome generally creates a picture with a more severe course. Brain anomalies, differences in facial structure, and serious organ problems can be more prominent.
While life expectancy is longer in individuals with Down syndrome, the prognosis can be more severe in cases of Trisomy 13 and Trisomy 18 due to severe organ anomalies.
Similar prenatal screening and genetic diagnostic methods are used in diagnostic processes.
What Are the Risk Factors for Patau Syndrome?
Although Patau syndrome mostly arises as a result of random chromosomal errors, certain risk factors do exist.
The main risk factors are:
- Advanced maternal age
- History of a previous pregnancy with a chromosomal anomaly
- Translocation carrier state in the family
- Genetic predisposition
- Chromosomal carrier states
Prenatal screening tests and genetic counseling processes are recommended, especially in advanced maternal age pregnancies.
Why Is Genetic Counseling Important in Patau Syndrome?
Genetic counseling is a quite important process for families diagnosed with Patau syndrome. Because families need both to reach accurate information about the disease and to perform a risk assessment in terms of future pregnancies.
During the genetic counseling process:
- Chromosomal analysis results are explained
- The course of the disease is evaluated
- The recurrence risk is discussed
- Prenatal diagnosis options are outlined
- Psychological support is provided
Especially in translocation-type Trisomy 13 cases, chromosome analysis of the parents can be performed. Thus, risk calculation for subsequent pregnancies can be planned in a healthier manner.
Follow-up Process in Babies with Patau Syndrome
The follow-up of babies with Patau syndrome requires a multidisciplinary approach. Because the disease affects not just a single system, but many organs.
Among the branches involved in the follow-up process are:
- Genetics
- Obstetrics and gynecology
- Neonatology
- Cardiology
- Neurology
- Pediatric surgery
- Physical therapy
- Psychological support units
.
Heart anomalies, feeding problems, neurological development, and respiratory functions must be evaluated regularly. Additionally, psychologically supporting the families is one of the important parts of the care process.